Nurses in the North Carolina hospital came upon the discovery after they noticed a rise in children testing positive for the THC. Instead of contacting the police, they began a study at the University of North Carolina at Chapel Hill as to why this new outbreak was happening.

Turns out it’s not truly THC that’s in the soaps. In fact, scientists can’t figure out why the test strips actually give false positives, but they do have some theories. According to My Health News Daily, they could be turning positive because “some of the compounds in the soap have a structure that is partly similar to THC, or it could be that chemicals in the soap change the way the test works.”

So how is it getting into the baby’s urine? Are the chemicals from the soaps being absorbed through the baby’s skin? Thankfully, no; it was actually found that, during the collection of the sample, the residue left on the baby’s skin was finding its way into it.

There are at least five different soaps listed that have been found to cause the issue. They include Johnson & Johnson’s Head-to-Toe Baby Wash, Johnson & Johnson’s Bedtime Bath, CVS Night-Time Baby Bath, Aveeno Soothing Relief Creamy Wash, and Aveeno Wash Shampoo.

“We really did this to help protect families,” said Dr. Carl Seashore of UNC-Chapel Hill who helped research the positive THC tests. Following the study, the hospital at UNC-Chapel Hill now sends all positive drug tests for further evaluation.